Understanding Typhoid Fever Transmission Dynamics in The Presence of Multiple Interventions– Optimal Control and Cost-Effectiveness Analysis

The consequences of typhoid fever in the host are a significant public health concern. Most nations in Sub-Saharan Africa, Asia, and North America are experiencing their highest rates of typhoid cases and deaths due to inadequate sanitation. This study focuses on a non-autonomous deterministic model that describes the spread of typhoid fever infections in human host communities. The model is built up by taking into account the optimal vaccination of susceptible births and immigrants, the treatment of infectious persons, and proper environmental sanitation. The new optimal control model was analyzed using Pontryagin’s maximal principle. The impacts of using various combination tactics incorporating the deployment of at least one of the three control interventions were demonstrated through numerical simulations. The simulation results demonstrate the effectiveness of each strategy in reducing disease prevalence. Using the incremental cost-effectiveness ratio (ICER), a cost-effectiveness analysis was performed to support the numerical results obtained from the numerical simulations of the optimality system. This aids in determining the most economical approach that can be used in places with limited resources, such as Nigeria.